Sumas Prairie is a landform in British Columbia, Canada and the State of Washington, United States. Part of the Fraser Lowland, it was created by the draining of Sumas Lake early in the 20th Century, and extends from the Vedder Canal southwestwards into northern Whatcom County, Washington. All of its Canadian portion, except its northeasternmost area around Yarrow, which is part of today's City of Chilliwack, was formerly the District of Sumas, which was amalgamated into the City of Abbotsford in 1972.
Map of Sumas Prairie, Abbotsford, BC, Canada
References
Sumas Prairie Wikipedia(Text) CC BY-SA